docs_deploy.yml - force rebuild attempt (#3502)

.github/workflows/docs_deploy.yml

@@ -90,4 +90,5 @@ jobs:
           git config --global user.email "${{ secrets.PX4BUILDBOT_EMAIL }}"
           git add ${BRANCH_NAME}
           git commit --amend -m "PX4 docs build update (vitepress) `date`"
+          git commit --allow-empty -m "Empty commit to force rebuild"
           git push origin main -f